// ===========================================================================
// Copyright 2018 Autodesk, Inc. All rights reserved.
//
// Use of this software is subject to the terms of the Autodesk license
// agreement provided at the time of installation or download, or which
// otherwise accompanies this software in either electronic or hard copy form.
// ===========================================================================
//
//
//  Creation Date:  27 Nov 1997
//
//  Description:
//      This procedure controls the behaviour of
//		the navigator buttons that appear at the
//		top of the attribute editor
//
//  Input Arguments:
//		$type = whether we're looking for forward or
//				backward connections
//		$menu = the popup menu control name
//				("" if the button is hit with the LMB)
//		$node = the name of the node
//		
//  Return Value:
//      None
//


global proc AEpropagateMenuCB(string $type, string $menu, string $node)
{

	if ( $menu != "" ) {
		setParent -m $menu;
		popupMenu -e -deleteAllItems $menu;
	}

	// get a list of all the plugs in the desired direction
	//
	string $allPlugs[];
	string $plugs[];
	if ( $type == "-backward" ) {
		// note: since we need to do an extra filtering step for
		// backward connections, we use a temporary string array ($allPlugs)
		//
		$allPlugs = `listConnections -s false -d true -c true -p true $node`;
	} else if ( $type == "-forward" ) {
		$plugs = `listConnections -s true -d false -c true -p true $node`;
	}

	// loop through the plugs and filter out those that are connected
	// to invalid attributes (only for backward connections)
	//
	int $i;
	if ( size($plugs) == 0 && size($allPlugs) > 0 ) {

		// get a list of attributes that we'll check for connections;
		// these attributes must be:
		//	visible
		//	connectable
		//	readOnly
		//
		string $attrs[] = `listAttr -visible -connectable -readOnly $node`;

		for ( $i = 0; $i < size($allPlugs); $i += 2 ) {

			// tokenize the indexed $allPlugs such that:
			//	currentNodeBuffer[0] is the nodeName
			//	currentNodeBuffer[1] is the attributeName
			//	currentNodeBuffer[2] would be the multi index if defined
			//
			string $currentNodeBuffer[];
			tokenize($allPlugs[$i], ".[]", $currentNodeBuffer);

			// search for the attribute name in the attribute list;
			// if we find it, add it to our list of valid plugs: $plugs
			//
			for ( $j = 0; $j < size($attrs); $j++ ) {
				if ( $currentNodeBuffer[1] == $attrs[$j] ) {
					// got a valid one
					$plugs[size($plugs)] = $allPlugs[$i];
					$plugs[size($plugs)] = $allPlugs[$i+1];
					break; // from $j loop
				}
			}

			// if we don't want a whole menu (i.e. just
			// do a showEditor on the first item in the
			// list) we can break from this loop if we've
			// got at least one plug
			//
			if ( $menu == ""  && size($plugs) > 0 ) {
				break; // from $i loop
			}
		}
	}

	// Remove unwanted nodes in pairs.
	//
	clear $allPlugs;
	$allPlugs = AEfilterUnwantedNodes($plugs, true);
	clear $plugs;
	$plugs = filterBlackBoxNodes( $allPlugs, true );
	
	// now we have a list of valid plugs;
	// depending on what we want to do with this list,
	// we can now either build a pop-up menu, or
	// simply show the first item in the list
	// in the attribute editor
	//
	string $currentNodeBuffer[], $connectedNodeBuffer[];
	if ( $menu == "" ) {
		// show the attribute editor for the first connection
		//
		if ( size($plugs) > 0 ) {
			tokenize($plugs[1], ".", $connectedNodeBuffer);
			showEditorExact $connectedNodeBuffer[0];
		}
	} else {
		// build the menuItems for the popup
		//
		for ( $i = 0; $i < size($plugs); $i += 2 ) {
			tokenize($plugs[$i], ".", $currentNodeBuffer);
			tokenize($plugs[$i+1], ".", $connectedNodeBuffer);
			string $command = ("showEditorExact "+$connectedNodeBuffer[0]);
			string $label = "";
			switch ( $type ) {
			  case "-backward":
				$label = ($currentNodeBuffer[1]+" -> "+$plugs[$i+1]);
				break;
			  case "-forward":
				$label = ($plugs[$i+1]+" -> "+$currentNodeBuffer[1]);
				break;
			  default:
				break;
			}
			menuItem -l $label -c $command;
		}
	}
}